Switch to terrorist hunt map
Once online, go to mission then return to team survival. Choose Hotel or Nuclear Facility. Instead of being the original map for it, it will be the Terrorist Hunt map. The terrorists are still in the game -- be careful. Also, it might have "0" next to the stars for your connection and it will not rise. This also makes it slightly more extreme to see if you and your opponents can work together, then afterwards kill each other.

NOTE: As their name suggests hints are not exactly Rainbow Six 3: Black Arrow cheats, and are usually just simple (but very useful) tips on how you can unlock secret level, features, find hidden areas and such. Hopefully these will make playing Rainbow Six 3: Black Arrow even more entertaining.

Bottom of the Ferry Boat Garage
When online go to the ferry boat. Go to the green team and get on top of the chairs. Your friend will make a ramp with his gun you will run up it. You will now be on the top of the chairs. Your friend will duck in front of you. Run on top of him and he will run to the edge. Warning: This will take off two bars of health.

Climbing Glitch
On some levels, especially ferry boat, you can climb on chairs and stuff to get in good spots. Get parallel to whatever you want to climb on and click the left Thumbstick really fast.